First attempt at ripping out agnostic code into ifcopenshell.api namespace. See #1399.

src/ifcopenshell-python/ifcopenshell/api/georeference/remove_georeferencing.py

@@ -0,0 +1,12 @@
+class Usecase:
+    def __init__(self, file, settings=None):
+        self.file = file
+
+    def execute(self):
+        map_conversion = self.file.by_type("IfcMapConversion")[0]
+        projected_crs = self.file.by_type("IfcProjectedCRS")[0]
+        if projected_crs.MapUnit and len(self.file.get_inverse(projected_crs.MapUnit)) == 1:
+            # TODO: go deeper for conversion units
+            self.file.remove(projected_crs.MapUnit)
+        self.file.remove(projected_crs)
+        self.file.remove(map_conversion)